Antiviral and antitumor antibiotics. XIV. Effects of ascochlorin and other respiration inhibitors on multiplication of Newcastle disease virus in cultured cells.

Antiviral activity on Newcastle disease virus was examined with some respiration inhibitors including ascochlorin, rotenone, antimycin A(3), piericidin A, dicoumarol, 2, 4-dinitrophenol, pentachlorophenol, and fatty acids. Of the chemicals tested, ascochlorin and rotenone showed significant inhibitory effect on the viral growth in cultured cells as determined by the plate and tube assay methods. Dose response of ascochlorin and rotenone was observed in rate and final yield of hemagglutinin synthesis. Ratio of infectivity for hemagglutinin was nearly equal at any test concentrations of ascochlorin. Thus, the possibility of inhibition of virus maturation by the antibiotic was excluded. Ascochlorin had no activity on virus particles and on viral adsorption onto host cells.